All of our servers are configured to GMT by default. It is possible, however, for you to adjust the date for PHP and this is done via a php_value directive in your .htaccess file.
The line you place in your .htaccess file looks like this:
php_value date.timezone "Europe/London"
A full list of available locations and time zones is available on php.net at http://php.net/manual/en/timezones.php